Cornell Maple Program 2019 – 2020 ANNUAL REPORT Cornell University Department of Natural Resources Authored by: Stephen Childs, Ailis Clyne, Aaron Wightman and Adam Wild 1 Program Overview Supporting the Maple Products Industry The Cornell Maple Program conducts research and extension with the goal of improving the production and use of maple products. Work toward this objective takes place in three parts: 1) infrastructure upgrades that create and enhance capacity in our two maple facilities 2) applied research on a broad array of topics related to maple production and profitability and, 3) extension programming to share knowledge across the industry. The Cornell Maple Program consists of maple specialists and technical support staff located at two facilities who work with a network of industry allies to deliver educational content. The Arnot Research Sugarbush near Ithaca, NY and the Uihlein Maple Research Forest in Lake Placid, NY include a combined capacity of over 14,000 taps in 350 acres of sugarbush, as well as modern processing equipment and research kitchen space. These two research and production facilities provide opportunities for experiments that account for region-wide variability in sugarbush conditions. Research sugarhouses at Arnot Forest in Van Etten, NY (left) and Uihelin Forest in Lake Placid, NY (right). 2 Program Highlights Sugarbush Management Super Sweet Trees Continuing the legacy of the “super sweet” maple tree project at the Uihlein Research Forest, we are in the middle of a three year project funded by McIntire Stennis federal capacity funds to re-analyze the potential sap sweetness and volume from our “super sweet” maple plantations. The project dates back to the 1960’s when the US Forest Service attempted to create trees with higher sap sugar content by grafting cuttings from sweet trees onto generic root stock. Seed collected from these trees was then planted and grown. In this project we are measuring the syrup production potential of both the grafted trees and the maples grown from their seed. The grafted trees, although large and beautiful, have had unremarkably low sugar not any better than the average sugar maple. It is believed that this is a result of the generic root stock they were grafted to. However, the trees grown from their seed, inherited the sweet sap genetics and all tend to be sweeter trees. Our highest season average sap sweetness tree was 8.3% (single day high of 12%) sugar with a handful of trees averaging 6-7% sugar. Not all were sweet though as there was a number of trees with an average 2% sap sweetness. As the trees are starting to produce seeds, it is time to remove the lower sugar trees before they cross-pollinate with the high sugar trees. Sugarbush Thinning With funding support from USDA NIFA and NYS Department of Agriculture and Markets, a long-term study is underway to measure the impact of thinning trees from a sugarbush on tree health and syrup production in the remaining stand. Data has been collected for two seasons pre-thinning, and 1 season after the thinning. Preliminary results indicate a positive growth response in the residual stand. The production of sugar, sap and syrup was showing a trend towards response to increased release of the crown, but the relationship is weak. The strength of response may require additional 3 time for trees to allocate energy reserves into starch (sugar) storage rather than growth following release. Sap Collection An effective sap collection system must effectively deliver vacuum to trees, keep tapholes productive, quickly move sap to the sugarhouse, and stay as clean as possible to protect product quality. Numerous projects are underway to improve collection systems. Line Cleaning For the second year, most mainlines in the Arnot Forest sap collection system were treated with a food grade washing and sanitation at the end of the sugaring season. The purpose was to develop an efficient washing system and evaluate cleaners. Washing solutions were mixed in a tractor mounted tank and sucked into the far end of mainlines with vacuum. In places where the end of the line was not accessible by tractor, a connector line was installed to reach the nearest roadway. For lines located more than 20 ft uphill from the road, a PTO powered roller pump was used to pump wash fluid to the line. Each line was treated with the following: Treatment Volume (gal) Chemistry Concentration Rinse 50 water NA Wash 50 sodium hydroxide 12.0 pH (RO soap) Rinse 50 water NA Sanitize 50 sodium 200 ppm (1 TBSP hypochlorite per gallon) Rinse 100 water NA Sap Flow Boosting Sap flow rate can have a significant impact on syrup quality. The speed of travel from tree to storage tank influences sap temperature and dissolved oxygen levels. 4 Slow moving sap is more prone to warming on sunny days which promotes microbial activity, leading to off-flavors, yeast laden sap and darker syrup. One possible remedy is utilizing vacuum to accelerate sap flow. Using vacuum eliminates the need for pumps powered by electricity or fuel which reduces maintenance requirements and allows systems to be placed in remote locations. Several configurations of vacuum pumps and specialized releasers have been tested for their ability to consolidate sap from several slow moving lines and accelerate it down a single conductor line. The most promising setup is a vertical releaser modified with a small air inlet on the discharge line. In our test system, sap reached the sugarhouse 2x faster without vacuum loss to the trees upstream from the releaser. More tests are scheduled for the 2021 sugaring season. Sap Ladders Moving sap uphill and across flat sections of sugarbush can be challenging. Sap ladders are one way to address this issue. To be effective a ladder must lift sap up the ladder and also conduct vacuum to the woods below the ladder. Traditional 5/16” ladders can waterlog and stop moving sap. They may also lose vacuum to the woods. We installed a demonstration ladder system with several alternative configurations side by side to compare performance. This system demonstrates the value of adding a 1” line to conduct vacuum and the limited usefulness of 3/16” tubing for ladders. Our 5 demonstration also showed the importance of a small, controlled air inlet at the bottom of the ladder for improving the flow rate up and preventing waterlogging. Flatland System Lack of slope is a challenge is some sugarbushes. In these flat systems, it is difficult to move sap without trucking or using pumping stations. The CMP installed and tested an alternative system that lifts sap uphill using a series of simplified ladders. In these ladders the mainline was bent into an S-shape instead of being cut. 6 As a result, the mainline is a continuous, unbroken line with 4 foot lifts every 60 to 100 feet. The system was tested with positive results during the 2020 season. Initial results indicate that the system was able to effectively move sap and also maintain vacuum. Lifting Sap with 3/16” Laterals We initiated a small study in 2019 to test the ability to pull sap uphill within a tubing system by using natural gravity vacuum created in 3/16” tubing on the downhill side. With a pocket of maples on the other side of the hill from our sugarhouse, we wanted to pull the sap up and over the hill to our sugarhouse without adding a vacuum pump. Trees on top of the hill with downhill sap flow created vacuum within the line that pulled the sap from the trees on the back side of the slope. The natural vacuum was enough to pull uphill from trees that were less than 20feet below the top of the hill. Any trees below this did not have enough vacuum to pull the sap uphill. Even at 15 feet below the top of the hill we still had 7.5inhg vacuum. With only the cost of a couple rolls of tubing and fittings we were able to make an additional 21 gallons of syrup from ~60 trees that we would not have access to otherwise. Tap Hole Sanitation Treatments to improve sanitation for the spout and drop line in tubing systems can increase sap yields by upwards of 100%. Check valve spouts, bac zap spouts with imbedded silver, spout and drop line sanitation, and spout and dropline replacement have all proven highly effective in boosting sap production. However, 3/16” lines do not maintain productivity with these practices. Evidence indicates productivity drops in these lines due to clogged fittings. If you look at a 3/16” fitting you will see that the opening is very small. Even a little yeast and mold can block this opening. Several treatments were studied to improve 3/16” performance during the 2020 sugaring season. These treaments included replacing fittings with new fittings, replacing fittings with ¼” fittings and cleaning tubing with calcium bleach. The ¼” fittings proved effective but were very difficult to install. Calcium bleach showed some promise but may need to be applied in a concentration higher that 200 ppm to bring performance back to the level of new tubing. 7 2020 3/16" Replicated Tubing Trials All new 3/16 4th year 3/16, new 1/4 T, new silver spouts 5th year 3/16, 3rd yer 5/16 drops, new spouts, sanitized with Ca bleach 4th year 3/16 with new 3/16 T new ck valve spout 4th year 3/16 with new 1/4 silver T, new 5/16 drop, new spout 4th year 3/16 with new spouts 4th year 3/16 with new 3/16 silver T, new 3/16 drop, new spout 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 Gal/tap more sap per tap Re-tapping Past studies of re-tapping have shown potentially large gains depending on the timing of the retap and sugaring weather.